1. FIELD OF THE INVENTION
The present invention relates to a novel polyhedrin gene and genetic engineering thereof. More particularly, it relates to a novel polyhedrin gene of Spodoptera litura nuclear polyhedrosis virus, vectors containing a heterologous sequence of DNA which is under the control of the polyhedrin promoter, recombinant viruses containing a heterologous sequence of DNA which is under the control of the polyhedrin promoter, cells infected with such recombinant viruses, methods of producing such vectors or recombinant viruses, methods of producing polypeptides using such recombinant viruses, a recombinant gene containing at least part of the polyhedrin gene replaced with a heterologous sequence of DNA, and a fusion peptide fused to at least part of the polyhedrin peptide.
2. DISCUSSION OF BACKGROUND
It is already known to produce useful substances by gene recombinant technology by means of baculoviruses. For example, U.S. Pat. No. 4,745,051 and European Patent Publications No. 0175852 and No. 0222412 disclose the production of useful substances by recombining the polyhedrin genes of the nuclear polyhedrosis viruses of Augrapha californica and Bombyx mori, respectively hereinafter referred to simply as AcNPV and BmNPV, respectively).
However, the vectors of AcNPV and BmNPV are as long as about 10 kilobase pairs by themselves, whereby at the time of cloning a gene coding for a useful substance with such vectors, the efficiency of transformation with Escherichia coli is poor, and it is difficult to clone a large gene encoding for a useful substance.
Thus, there remains a need for a method for producing polypeptides free of the above-described drawback. There also remains a need for polyhedrin genes, recombinant genes, vectors, recombinant viruses and cells infected with such recombinant viruses which can be used in such a method and there is also a need for methods to produce such vectors and recombinant viruses.